Detectable urogenital schistosome DNA and cervical abnormalities 6 months after single-dose praziquantel in women with Schistosoma haematobium infection

Abstract

We explored response to single-dose praziquantel therapy in a cohort of 33 women with Schistosoma haematobium infection in rural Mwanza, Tanzania. Women with S. haematobium infection confirmed both by eggs in urine and by polymerase chain reaction (PCR) received single-dose praziquantel and treatment of concomitant sexually transmitted infections. Macroscopic cervical abnormalities were also quantified. After 6 months, microscopically detectable egg excretion was eliminated, but 8 of 33 women (24%) were persistently positive for S. haematobium by PCR, and 11 (33%) had cervical abnormalities potentially attributable to schistosomiasis. This suggests that praziquantel treatment more frequently than every 6 months may be necessary for complete elimination of the parasite and prevention of genital tissue pathology. This aggressive therapy may in turn play a key role decreasing HIV susceptibility in millions of people living in regions in which S. haematobium is endemic.

Keywords: Schistosoma haematobium; Tanzania; female urogenital schistosomiasis; polymerase chain reaction; praziquantel.

Figure 1

Pre- and Post-Treatment Urine Egg, Urine Schistosome PCR, and Cervical Lavage Schistosome PCR. Results for each patient are shown at the time of praziquantel treatment (Month 0) and follow-up examination six months later (Month 6). PCR, Real-Time Polymerase Chain Reaction to detect schistosome DNA. Thicker dark line indicates the mean value of all women tested (n=33).